# CVE-2026-54452: safeurl: Missing IPv6 CIDR Ranges in Blocklist

> Attackers can bypass SSRF protections in safeurl by targeting omitted IPv6 ranges when IPv6 support is explicitly enabled.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Sep 2026
- **Updated:** 16 Sep 2026
- **Also known as:** GHSA-xgch-x3mx-cm3c, GO-2026-5997

## What is CVE-2026-54452?

CVE-2026-54452 is a medium-severity server-side request forgery vulnerability in doyensec safeurl, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

safeurl is a server-side request forgery protection library. Prior to 0.2.4, the privateNetworks list in ip.go omits the IPv6 ranges 64:ff9b:1::/48, 5f00::/16, 3fff::/20, and 100:0:0:1::/64. When an application enables IPv6 with EnableIPv6(true), an attacker-controlled destination in one of these ranges is not recognized as non-public and can pass the SSRF destination check, potentially allowing access to resources hosted within the omitted ranges. IPv6 is disabled by default, and configurations that retain EnableIPv6(false) are not exposed to this bypass. This issue is fixed in version 0.2.4.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-54452?

3 open source packages ship an affected version, including github.com/doyensec/safeurl.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/doyensec/safeurl` | Go | All versions | 0.2.4 |
| `github.com/doyensec/safeurl` | Go | All versions | 0.2.4 |
| `github.com/doyensec/safeurl` | Go | All versions | 0.2.4 |

## How do I fix CVE-2026-54452?

Upgrade github.com/doyensec/safeurl to 0.2.4 or later.

## Is CVE-2026-54452 being exploited?

There is no known exploitation of CVE-2026-54452 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54452 and fix it if it is affected.

What it is: CVE-2026-54452 is a medium-severity server-side request forgery vulnerability in doyensec safeurl, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-54452 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/doyensec/safeurl (Go): affected all versions; fixed in 0.2.4
- github.com/doyensec/safeurl (Go): affected all versions; fixed in 0.2.4
- github.com/doyensec/safeurl (Go): affected all versions; fixed in 0.2.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54452/ (Markdown: https://insights.sbomify.com/CVE-2026-54452/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54452
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54452
- OSV: https://osv.dev/vulnerability/CVE-2026-54452

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54452/
Summaries are generated and may contain mistakes; the official description above is the record.